Bob weight for a stock 426 hemi engine?

[polyjohn]

Hello Folks,

Took my crank, rods and pistons for a balance and the guy can't do it?
He can't believe the Bob weight is over 3kgs approx. 3.113grams.

They don't keep enough weights to do that amount of balancing.
Is the 3.113grams sound about right or has he made a mistake?

Thanx in advance from John

 

[Bird 426]

Heavy rods. I put H-beams in mine. Pictures of the weight that was removed, a little over 4 lbs. May be why he didn't want to balance it. I really liked that weight that was welded to the flange!

 

[33 IMP]

He's probably not wrong.
I have a billet hemi crank (cracked top alcohol crank) with fourteen slugs of mallory in it.
And an original maxwedge crank with weights welded to the counterweight
Changing from the domed ashtrays that somebody thought were pistons to 12 to 1 Arias, reduced bobweight by more that 400 grams. I used a steel 440 crank instead.

 

[dvw]

He's probably not wrong.
I have a billet hemi crank (cracked top alcohol crank) with fourteen slugs of mallory in it.

If they are stock pistons and rods on an aftermarket crank it's going to be tough to balance. Those cranks are generally conterweighted for wedge pistons and aftermarket rods. My 4.500" stroke/4.530" wedge with a 7.100" steel rod is 2367 grams. With a lighter piston and thinner pin it was 2222 grams.
Doug

 

[rickseeman]

As Doug said most of these cranks today that they call Hemi cranks are really wedge cranks. You have to have really light components to get under 2500 grams. (I think that's what an Eagle crank starts out with.) And some are lighter than that. Nothings easy about building a Hemi today.

 

[polyjohn]

Thank you for the replies Guys!

Stock hemi crank with stock rods and 12 to 1 stock pistons too.
Yep its rare stuff here in the UK as well, he has never seen a PLUS 3kgs bob weight...

I have found another shop but its 300 miles away, but to you guys its nearly next door!
Best wishes from a hemi lover, ''can you say HEMI'', I can...

On a different note I have an ex Weslake dyno engine from the late sixties.
Its a 426 wedge engine with Nascar rods and custom pistons.

I believe its a 1971 replacement engine for Nascar after the hemi ban.
One off casting iron street heads from Mother Mopar.

Ovalport intakes and D-port exhausts with a passenger car crossover unlike the max-wedge.
Only pair ever made for Nascar and possibly street cars in the 70's?

 

[dvw]

I believe those were done by Westlake. I know a guy that worked at Koffel's that was a local oval guy. He had a pair that he raced with.
Doug

 

[polyjohn]

They were cast by mother Mopar in the late sixties to overcome the hemi ban.
Passenger car ''W1 heads'' never made it into production.

2.250 intake valves and 1.780 exhaust valves nice.
Extra cooling passages like the late MH heads too.

 

[RemCharger]

They were cast by mother Mopar in the late sixties to overcome the hemi ban.
Passenger car ''W1 heads'' never made it into production.

2.250 intake valves and 1.780 exhaust valves nice.
Extra cooling passages like the late MH heads too.

View attachment 1950235

View attachment 1950237

View attachment 1950239

Wow that's pretty neat. Look how thick the deck is between spark plugs. Also strange they used open chambers.

 

[33 IMP]

That's a BIG BLOCK head?!?
Sure doesn't look like any bbm head I've ever seen.
Looking at the port pics, I thought it was a W2 small block head.